Analysis of CO2 transfer processes involved in global trade based on ecological network analysis

A large share of total global CO2 emissions results from the production processes of internationally traded goods and services. Such emissions have been referred to as virtual or embodied CO2 flows. Hence, it is important to understand the directions, locations, and drivers of carbon flows resulting from global trade. To analyze these flows, hotspots, divisions of labor, and directions of flows in the global production and consumption web, we applied a multi-national framework based on a combination of multi-region input-output tables with ecological network analysis. We found that the CO2 flows between the 40 key countries within the network doubled between 1996 and 2011, and the trade-related emission hub shifted from Europe to Asia. We analyzed a large number of CO2 transfer paths and their changes over time. We found that the United States participated the most in big paths, including those that represent carbon flows between the United States and both developed and developing countries, whereas developing countries such as China and India participated more in the fast-growing paths, and especially in paths between pairs of developing countries. In contrast, traditionally active countries, including Russia and Germany, grew at a slower rate, resulting in a progressively smaller share in the global system. Taking these large and important CO2 transfers into consideration, we proposed adjustments to the national mitigation targets set by the Paris Agreement.